1. Field of the Invention
The present invention relates to a color picture display apparatus for monitoring colors of a picture based on picture signals picked up by a imaging camera, which is capable of displaying the picture of desired colors such as actual colors on different displays regardless of different luminous characteristics thereof.
2. Description of the Prior Art
In a conventional color picture display apparatus for monitoring colors of a picture for use in an electronic endoscope or the like, a color correction of a monitor is carried out by determining exponential factors of gamma characteristics to 2.2, that is, by raising to 1/2.2 power in a photographing camera side. However, in an actual monitor, the exponential factors of the gamma characteristics are not always 2.2, and further the gamma characteristics values are not the same in luminous bodies of three colors such as red, green and blue. The chromaticity of the luminous bodies of the three colors are different from one another depending on different manufacturers, and the chromaticity of the luminous bodies varies even when the luminous bodies are manufactured by the same manufacturer. Further, in the same monitor, it is difficult to maintain the same colors from the same color picture signals R, G and B of the three colors by the deterioration of the luminous bodies due to a change with the passage of time and the like.
Therefore, in the conventional color picture display apparatus of this kind, even when the color correction of the color monitor is carried out in the camera side, the desired colors, for instance, the actual colors cannot be obtained very often, in practice. Such color differences of the pictures displayed on a display brings about a large trouble in the color monitor for the electronic endoscope which requires the real colors of the pictures on the monitor as an important factor for a diagnosis.
In another conventional color picture display apparatus, monitor characteristics of each color display are measured, and then color correction values are obtained from the monitor characteristics. Then, the picture signals obtained by photographing the object are corrected on the basis of the color correction values. However, usually, such a measuring apparatus is not provided to each color monitor but to a particular place such as a factory and a service station. Accordingly, this correction operation can be performed only on forwarding the color monitor from the factory or on inspecting the color monitor in the service station.